How an engine will be lubricated is just as important as any other design detail when developing new dual-fuel engines,Dr Bartosz Rozmyslowicz, WinGD’s Senior Expert, Fuels and Lubricants, tellsThe Motorship
Two-stroke engine builder WinGD has set itself a goal of delivering its first engine running on ammonia in 2025. Just weeks after it declared that ambition in November last year, it opened a new global test centre in Shanghai in cooperation with China Shipbuilding Power Engineering Institute to focus on, among other things, new fuels including methanol and ammonia.
Source: WinGD
Dr Bartosz Rozmyslowicz, WinGD’s Senior Expert, Fuels and Lubricants
Then in June this year it announced it is collaborating with Hyundai Heavy Industries’ Engine Machinery Division to deliver the first WinGD engine able to run on ammonia and reaching that landmark will involve “developing relevant safety, emissions abatement and fuel supply solutions for ammonia engines”, a WinGD statement said at the time.
It will also need to address lubrication. “We always treat the lubricant as a component of our engine”, Dr Bartosz Rozmyslowicz, WinGD’s Senior Expert, Fuels and Lubricants, told The Motorship. But when it comes to selecting lubes for ammonia-fuelled engines, “where to start?”
It has long experience of validating lube oils for use with engines running on such fuels as LNG, methanol and other potential future marine fuels, since engines are already available that use these fuels and can be used for tests with potential new lube formulations. But ammonia is not widely used in any sector and “there is no marine engine that you can use to test this fuel”, he said, so when it comes to selecting a suitable lubricant, “we start from zero”.
“The first thing we need to know is whether current types of lubricants are suitable for ammonia engines” – either for running engine tests or for long-term use – or whether new lubricants will be needed, he said. “Nobody can yet answer that.”
Ammonia presents novel challenges because “it is more corrosive than any fuel ever used” in marine engines. It is a reactive gas that forms a basic solution with water, giving it “unique properties that might endanger the engine”, he explained.
Because of these uncertainties, “we don’t know how ammonia will interact with lubricant additives”, he went on. “We hope that current formulations are suitable and there will be no interactions between them and ammonia, but we do not know that,” Mr Rozmyslowicz said. In particular, he is keen to understand whether any interactions will affect piston running.
Although ammonia is a base when in contact with water, it burns to form acidic compounds that will need neutralising by the lube oil, in much the same way as sulphurous emissions. So one consideration is whether the initial basic phase of the injection process lasts long enough to influence the lubrication regime.
“It will get burned; so there will not be much left”, Mr Rozmyslowicz said, in which case its initial presence as a base should not cause any problems. “However, we have to always consider that ammonia will be present at a certain concentration in the combustion chamber and in the lubricant, which has to be considered, also from the safety point of view”, he added.
To understand these potential impacts, WinGD is cooperating with oil companies that are developing suitable oils, he said. WinGD specifies the minimum criteria for the oil to be operated in its engines and “We are trying to find common ground for development because we need to be sure that our engines will run reliably and they need to know that their lubricants will perform and not cause issues”, he continued. And these details need to be explored early enough “to be sure that, when the day comes, these engines will perform properly”.
What matters to its customers, he said, is that “they can expect this development to be completed in time before the first engine is delivered to them”.
